Campaigners have called on the Chancellor to defer a planned 20 pence per litre tax increase on sustainable biodiesel produced from used cooking oil, as London taxi drivers who will be affected by the change sounded their horns in protest outside the Treasury.

Speaking on BBC London Radio’s breakfast programme, Liberal Democrat deputy leader and biodiesel user Simon Hughes MP called on the Chancellor to delay the increase for 12 months, claiming taxi drivers had “a good case”.

Campaigners fear the increased tax will make used cooking oil biodiesel uneconomic, forcing current users to return to fossil fuels and leading to greater carbon emissions, substantial biodiesel industry job losses, and millions of litres of used cooking oil being thrown away as waste.

More than 1,000 London taxis and approximately 10% of the UK’s HGV fleet uses biodiesel produced from used cooking oil.

Tracey O’Keefe, director of the UK Sustainable Biodiesel Alliance and co-ordinator of the SOS Biodiesel campaign, said: “It beats me why the ‘greenest government ever’ would want to put 20 pence per litre on the cost of a green fuel made from waste; put 3,000 people on the dole at a cost to the taxpayer; and force responsible vehicle fleets to return to using fossil fuels and so increase carbon emissions. I think it’s time for a rethink, Chancellor.”